Rotary combustion air cooling arrangement

ABSTRACT

Disclosed herein is a rotary combustion engine comprising a plurality of cooling fins extending radially outwardly from a hollow housing in generally parallel relation to a rotor shaft rotatably journaled by end walls interconnected with the hollow housing, a fan driven by the rotor shaft, a shroud enclosing the fan and including an air inlet and an air outlet, wall means including a first portion engaging the radially outer ends of the cooling fins to provide a first plurality of cooling passages extending axially of the housing, and a second portion extending from the first portion and cooperating with the shroud to define a conduit extending from the shroud outlet to the first plurality of cooling passages, a second plurality of cooling passages extending arcuately along the outer surface of one of the end walls, a third plurality of cooling passages extending arcuately along the outer surface of the other of the end walls, and duct means independently communicating each of said second and third pluralities of cooling passages with said shroud outlet independently of each other and of the conduit.

Unite States Patent 1191 Donohue et al.

[ Nov. 5, 1974 ROTARY COMBUSTION AllR COOLING ARRANGEMENT [75]Inventors: James A. Donahue, Milwaukee;

John H. Winston, Menomonee Falls; Harry M. Ward, Illl, Waukegan, all ofIll.

{73] Assignee: Outboard Marine Corporation,

Waukegan, ll].

22 Filed: Jan. 8, 1973 21 Appl. No: 321,694

52 us. (:1. 123/8101, 418/101 [51] Int. Cl. F02b 55/12 [58] Field oilSearch 418/101; 123/801 [56] References Cited UNITED STATES PATENTS2,079,192 5/l937 Upshaw 418/101 UX 2,969,049 l/l96l Dillenberg 1 14l8/l0l X 3,196,850 7/1965 Jones 1 1 1 4l8/l0l 3,234,922 2/1966 Froede4l8/l0l UX 3,302,623 2/1967 Zimmermann 4l8/l0l X 3,369,529 2/1968 Jordan418/101 X Primary Examiner-Clarence R. Gordon Attorney, Agent, orFirmMichael, Best & Friedrich [5 7] ABSTRACT Disclosed herein is arotary combustion engine comprising a plurality of cooling finsextending radially outwardly from a hollow housing in generally parallelrelation to a rotor shaft rotatably journaled by end wallsinterconnected with the hollow housing, a fan driven by the rotor shaft,a shroud enclosing the fan and including an air inlet and an air outlet,wall means including a first portion engaging the radially outer ends ofthe cooling fins to provide a first plurality of cooling passagesextending axially of the housing, and a second portion extending fromthe first portion and cooperating with the shroud to define a conduitextending from the shroud outlet to the first plurality of coolingpassages, a second plurality of cooling passages extending arcuatelyalong the outer surface of one of the end walls, a third plurality ofcooling passages extending arcuately along the outer surface of v theother of the end walls, and duct means independently communicating eachof said second and third pluralities of cooling passages with saidshroud outlet independently of each other and of the conduit.

15 Claims, 9 Drawing Figures PATENTEBIW 5 I974 I ROTARY COMBUSTION AIRCOOLING ARRANGEMENT BACKGROUND OF THE INVENTION The invention relatesgenerally to rotary type internal combustion engines such as disclosedin the Jones U.S. Pat. No. 3,196,850, issued July 27, 1965. Moreparticularly, the invention relates to arrangements for air cooling suchengines. One example of a prior arrangement for air cooling a rotaryinternal combustion engine is disclosed in said Jones U.S. Pat. No.3,196,850.

In the Jones U.S. Pat. No. 3,196,850, the engine includes an air duct orplenum which extends from a fan axially of the engine and whichcommunicates successively, one after the other, with cooling passagesalong the end wall adjacent to the fan. with circumferentially extendingair passages around the hollow housing and with air cooling passagesalong the end wall remote from the fan. As a consequence, there is adecreasing pressure gradient extending axially along the duct, whichdecreasing pressure gradient progressively adversely affects cooling airflow through the cooling passages in the direction from adjacent to thefan to the end of the engine remote from the fan.

SUMMARY OF THE INVENTION The invention provides an air coolingarrangement for a rotary internal combustion engine wherein the fancommunicates separately or directly with end wall cooling passages andwith cooling passages along the hollow housing, as compared toarrangements including sequential or successive communication as, forinstance, in the Jones U.S. Pat. No. 3,196,850.

The invention also provides an air cooling arrangement for a rotaryinternal combustion engine in which the hollow housing is provided withcooling fins or passages which extend axially of the engine and in whichall of the cooling passages have substantially equal access to the airdelivered by the fan and are subject to substantially the same pressurehead.

The invention also provides an air cooling arrangement for a rotaryinternal combustion engine wherein the end wall remote from the fan isprovided with cooling passages which communicate directly with the fan(separately from the supply of cooling air to the hollow housingpassages) through a duct in the hollow housing and so as thereby to haveavailable substantially full fan pressure for pumping air through theremote end wall cooling air passages. More specifically, in thedisclosed construction, the only loss of head as between the coolingpassages along the adjacent end wall and the cooling passages along theremote end wall involves pressure losses due to flow through the duct inthe hollow housing.

One of the principal objects of the invention is the provision of an aircooling arrangement for a rotary internal combustion engine in which thehollow housing is cooled by axial flow cooling passages.

Another of the principal objects of the invention is the provision of arotary internal combustion engine in which cooling passages associatedwith the adjacent and remote end walls, as well as cooling passagesextending along the hollow housing, communicate in parallel relationwith the fan as compared with communi cation in series with the fan,i.e., as compared to successive communication with a single outlet ductleading from the fan.

Another principal object of the invention is the provision of a coolingarrangement for rotary internal combustion engines in which passagewaysor ducts leading to the end wall passages and to the axial coolingpassages along the hollow housing communicate with a common outlet froma fan shroud so as to substantially reduce variation in the pressurehead available to the cooling passages extending along the hollowhousing and along the adjacent and remote end walls.

Other objects and advantages of the invention will become known byreference to the following description, claims, and accompanyingdrawings.

THE DRAWINGS FIG. 1 is a side elevational view, partially broken awayand in section, of a rotary internal combustion engine embodying variousof the features of the invention.

FIG. 2 is a sectional view taken generally along the line 2-2 of FIG. 1.

FIG. 3 is a somewhat reduced sectionalview taken generally along line 33of FIG. 1.

FIG. 4 is a somewhat reduced sectional view, with portions broken away,taken generally along line 44 of FIG. 1.

FIG. 5 is a somewhat reduced sectional view, with parts broken away,taken generally along line 5-5 of FIG. 11.

FIG. 6 is a somewhat reduced sectional view, with parts broken away,taken generally along line 6-6 of of FIG. 1.

FIG. 7 is a fragmentary sectional view taken generally along line 77 ofFIG. 2.

FIG. 8 is a perspective view of one end of the rotary internalcombustion engine shown in FIG. 1.

FIG. 9 is an enlarged perspective view of the undersurface of a portionof the inner shroud member incorporated in the rotary internalcombustion engine shown in FIG. 1.

Before explaining the invention in detail, it is to be understood thatthe invention is not limited in its application to the details ofconstruction and arrangement of parts set forth in the following generaldescription or illustrated in the accompanying drawings, since theinvention is capable of other embodiments and of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation.

General Description Illustrated in FIG. 1 is a rotary internalcombustion engine 11 which includes a hollow housing or member 13 formedwith peripheral inner wall 15 having aninterior surface in the form of atrochoid. Connected to the ends of the hollow housing 13 are a pair ofspaced end walls 117 and 19 which, together with the hollow housing 13,define a cavity including a rotary, variable volume combustion zonedefined by the housing 13 and the rotating rotor 25. Carried in thecavity 21 on a rotor shaft 23 journaled in the end walls 117 and I9 is athreesided rotor 25. Extending through the hollow housing 13 are intakemeans 27 for admitting into the chamber or cavity 21 an air-fuel mixturein response to rotor rotation and an exhaust discharge means or outlet29 af fording outflow of the products of combustion from the chamber orcavity 21 in response to rotor rotation. Lo-

cated between the intake means 27 and the exhaust discharge means 29 isa spark plug 31 which is periodically fired to explode the air-fuelmixture. As a consequence of the foregoing construction, the hollowhousing 13 includes a sector 33 which extends from both sides of thespark plug 31 and which, during operation, is relatively hot as comparedto the remainder of the hollow housing 13.

In order to cool the sector 33 of the hollow housing 13, the hollowhousing 13 is provided throughout the sector and in accordance with theinvention, with a plurality of closely spaced, axially extending coolingfins 37 extending radially outwardly and in generally parallel relationto the rotor axis.

In order to cool the end walls, the end wall 17 is provided (Seeespecially FIG. with two arcuately spaced series 43 and 45 of closelyspaced cooling fins 47 extending axially and partially circumferentiallyaround the rotor axis and from an intermediate area or plenum space 49into which cooling air is delivered for further travel in oppositedirections between the cooling fins 47. In addition, the end wall 19 isprovided (See especially FIG. 6) with two arcuately spaced series 53 and55 of closely spaced cooling fins 57 extending axially and partiallycircumferentially from an intermediate area of plenum space 59 intowhich cooling air is delivered for further travel in opposite directionsbetween the cooling fins 57.

In order to supply air for travel over the cooling fins 37, 47 and 57,an air delivery system is provided. In accordance with the invention,the air delivery system includes (See FIG. I) a fan 63 mounted on anddriven by a portion of the rotor shaft 23 extending exteriorly of theend wall 17, together with a shroud 65 which encloses the fan 63 andincludes an inlet 67 co-axial with the fan 63 and (See FIG. 4) anarcuately extending discharge outlet 69 aligned axially with the areaoccupied by the hollow housing cooling fins 37. The air delivery systemfurther includes wall means in the form of an arcuate plate 75 (SeeFIGS. 1, 4, 5, 6, and 8) including a first portion for shrouding orcovering the radially outer ends of the hollow housing cooling fins 37so as to form between the fins 37 a plurality of cooling passages 77which are open at each end adjacent to the end walls 17 and 19. Stillfurther, the air delivery system includes a duct or conduit 81 which(See FIGS. 1, 4 and 5) is formed, in part by another portion of theplate 75 and which extends between the shroud discharge outlet 69 andthe adjacent ends of the hollow housing cooling air passages 77.

Respective cooling air passages 87 and 97 are also formed (See FIGS. 5and 6) along each of the end walls 17 and 19 by attachment thereto ofcovers 101 and 103 which engage the axially outer edges of the coolingfins 47 and 57.

Air is supplied to the cooling passages 97 associated with the end wall19 remote from the fan 63 by including in the hollow housing 13 (SeeFIGS. 2 and 7) an ax ially extending conduit, passage, or duct 105located in adjacent relation to the cooling fins 37. Further, in thisregard, the remote end wall 19 includes (See FIGS. 2 and 7) athree-sided portion 107 which meets with the adjacent end of the duct105 in the hollow housing 13 and includes a curved wall 109 whichdeflects the incoming air toward the plenum space 59 (See FIG. 6)between the arcuately spaced series 53 and 55 of cooling fins 57 orpassages 97.

More specifically, the shroud 65 is formed (See FIGS. 1, 3 and 4) at oneend of the engine 11 from inner and outer members 111 and 113respectively, with the inner shroud member 111 being suitably fixed tothe adjacent end wall 17 in engagement with the arcuately spaced series43 and 45 of cooling fins 47, thereby providing the before-mentionedcover 101. As already indicated, such engagement of the inner shroudmember 111 with the ends of the cooling fins 47 defines (See FIG. 5) thecooling passages 87 which extend in opposite directions from the supplyplenum 49 which communicates with the shroud outlet 69.

The outer shroud member 113 (See FIGS. 1. and 3) is suitably fixed tothe inner member 111 so as to in clude therein the fan 63 which ispreferably of the centrifugal or radial type and which includes a seriesof radially extending forwardly curved vanes 115 and a circumferentiallyextending radial discharge area or opening 117 (See FIG. 1) locatedbetween upper and lower flanges 119 and 121. The outer shroud member 113is formed with the air inlet 67 which affords axially inward air flowinto the fan 63. The periphery of the outer shroud member 1 13 aroundthe air inlet 67 forms (See FIG. 1) a labyrinthine seal 123 with aportion of the fan 63 and is connected to walls forming a spiralling,doughnut-like shroud portion 131 which extends radially outwardly fromthe fan 63.

As shown best in FIGS. 3 and 4, the spiralling portion 131 of the shroud65 extends in the clockwise direction, i.e., the direction of intendedrotor rotation as indicated by the arrow in FIG. 3, from about 10:00oclock to about I100 oclock' (12:00 oclock being at the top of the view)for a total arcuate distance of about 450. The shroud 65 is formed so asto deliver air to the outlet 69 to maintain an approximation of uniformpressure at the outlet 69. In this regard, the radial dimension of thespiralling shroud portion 131 gradually increases from 10:00 until about6:00 oclock, thereafter decreases until about 9:00 oclock, thereafterincreases to about 10:00 oclock, and thereafter decreases to about 1:00oclock.

In addition, the outer shroud member provides a transversely extendingceiling or upper wall 133 along the length completely around thespiralling shroud portion 131, and the inner shroud member 111 providesa transversely extending floor 135 along the bottom of the spirallingshroud portion 131 between about 10:00 oclock and about 7:00 oclock,thereby permitting at least a part of the air which flows radially andarcuately outwardly from the fan 63 into the shroud 65 to rotate in aclockwise direction, as seen in FIGS. 3, 4 and 5, to the area betweenabout 7:00 oclock and I100 oclock. The height of the ceiling 133 abovethe floor 135 gradually increases from about 10:00 oclock to about 8:00o'clock and thereafter remains substantially constant. The floor 135 isgenerally planar, except (See FIG. 4) for an inclined ramp 141 whichextends from an elevated position at about 10:00 oclock to about 3:00oclock where the ramp 141 merges into the floor 135. In addition, aninclined ramp 143 (See FIGS. 4, 5 and 6) extends downwardly below thefloor 135 from about 6:00 oclock to about 7:00 oclock and to a positionof engagement with the hollow housing 13 adjacent to the end of the duct105. In the area between about 7:00 oclock and 1:00 oclock, the innershroud member 111 terminates (See FIGS. 4 and 5) along an edge 137 ininwardly spaced relation from the plate 75 which extends from the outerwall 136 (See FIG. 3) of the outer shroud member 113 to thereby definethe shroud outlet 69 which extends between about 7:00 oclock to about1:00 oclock.

The shroud outlet 69 communicates separately with the cooling airpassages 97 in the remote end wall 19 through the duct 105 in the hollowhousing 13, sepa rately with the plenum 19 space between the arcuatelyspaced air passages 87 along the adjacent end wall 17, and separatelywith the axially extending air passages 77 along the hollow housing 13.In this regard, the communication between the shroud outlet 69 and theend wall passages 87 and 97 occurs approximately between 7:00 and 8:00oclock, and the communication between the shroud outlet 69 and the axialpassages 77 along the hollow housing 13 extends from approximately 8:00to about 1:00 oclock.

Further in regard to communication between the end wall passages 87 and97 and the spiralling shroud portion 131, the inclined ramp 143extending from in the area of about 6:00 oclock to about 7:00 oclock andfrom the floor 135 provided by the inner shroud member 1113 leads thearcuately flowing air axially inwardly to the axial duct 105 in thehollow housing 13 leading to the air passages 97 in the remote end wall19 and to the plenum space 49 at the adjacent end wall 17.

A further portion of the inner shroud member 111 in the form of anaxially inwardly extending flange 151, shown best in FIGS. 5 and 9, isalso employed to separate air flowing to the remote end wall coolingpassages 97 from the air flowing to the adjacent end wall coolingpassages 87 and to deflect air toward the plenum space 49. Still furtherin addition, a pair of curved deflectors 153 and 155 (See FIGS. 4, 5 and9) extend from the inner shroud member surface 157 (See FIG. 9) adjacentto the end wall 17 so as to deflect air incoming from the shroud outlet69 for travel into the plenum space 49 and through the end wall coolingpassages 87.

In operation, rotation of the rotor 25 causes common rotation of the fan63 which inhales cooling air through the shroud inlet 67 and whichdischarges cooling air radially outwardly into part of the spirallingshroud portion 131 between about l:00 oclock and 7:00 oclock formovement arcuately toward the end of the shroud outlet 69 at about 7:00o'clock, and for travel to the end wall cooling passages 87 and 97 andfor travel through the duct 81 to the axially extending passages 77along the hollow housing. In addition, the fan 63 also dischargescooling air radially outwardly and in the clockwise direction, as seenin FIG. 4, over the edge 137 into the shroud outlet 69 between about7:30 and about l0:00 oclock for travel through the duct 81 into theaxial cooling passages 77 extending along the ho]- low housing 13.

The form of the shroud 65 in the area of the shroud outlet 69, i.e.,from about 7:00 oclock to about 1:00 oclock, serves to create an area ofsubstantially uniform pressure so as to afford substantially equalcooling air flow through all of the axially extending passages 77. Atthe ends of the hollow housing 13 from the fan, the cooling air exitsdirectly from the passages 77 into the environment.

in addition, cooling air is also supplied through the outlet 69 from theshroud 65 to both of the end wall passages 87 and 97 for flow around theaxis of the rotor 25 and radially outwardly directly into theenvironment. The head developed by the fan 63 is available to the endwall cooling passages 97 independently of air supply to the axialpassages 77 and the end wall passages 87. In addition, air is suppliedto the end wall cooling passages 87 independently of the end wallcooling passages 97 and the axial cooling passages 77, and air issupplied to the axial cooling passages 77 independently of the end wallcooling passages 87 and 97. Furthermore, the axial passages 77 extendingalong the hollow housing 13 are subject to substantial uniform pressurehead, and the same pressure head is generally available in the plenumspaces 49 and 59 at the adjacent and remote end walls 17 and 19, exceptonly for flow losses occurring in the axially extending housing duct 105during travel to the remote plenum space 59. As a result of theforegoing construction, variation in pressure head available at theentrance to all of the various cooling passages 77, 37 and 97 issubstantially minimized.

ln addition, the arrangement for separately supplying cooling air toeach of the end wall passages and to the axially extending housingpassages is also applicable to housing passages which, while alsoextending axially, also extend, at least in part, at an angle to thehousing axis. Such an arrangement would permit flow from the shroud tothe housing passages in a manner avoiding a relatively sharp change indirection.

Various of the features of the invention are set forth in the followingclaims.

We claim:

1. A rotary combustion engine comprising a hollow housing, a pair ofspaced end walls interconnected with said hollow housing to form acavity, a rotor shaft extending in said cavity and rotatably .journaledby said end walls, fuel intake means communicating with said cavity,exhaust discharge means communicating with said cavity, a combustionzone in said cavity between said intake means and said exhaust dischargemeans, whereby said housing includes a sector which extends between saidintake means and said exhaust discharge means and which is relativelyhotter than the remaining portions of said housing, a plurality ofcooling fins extending radially outwardly from said housing sector ingenerally parallel relation to said rot-or shaft, a centrifugal fandriven by said rotor shaft and having a circumferentially extendingradially open outlet, a shroud defined by first wall means enclosingsaid fan and extending radially outwardly from said fan outlet, saidshroud communicating with said radially open circumferentially extendingfan outlet and including a shroud dis charge outlet, and second wallmeans including a first portion engaging the radially outer ends of saidcooling fins to provide a plurality of cooling passages extendingaxially of said housing, and a second portion extending from said firstportion and cooperating with said shroud to define a duct extending fromsaid shroud discharge outlet to said plurality of cooling passages.

2. A rotary combustion engine in accordance with claim 1 wherein saidshroud further includes an axially inner member mounted on one of saidend walls and an axially outer member mounted on said inner member andhaving therein an air inlet for said fan.

3. A rotary combustion engine in accordance with claim 2 wherein saidair inlet is concentric with said rotor shaft.

4. A rotary combustion engine in accordance with claim 1 therein saidshroud discharge outlet has a limited arcuate extent and is alignedarcuately with said cooling passages.

5. A rotary combustion engine in accordance with claim 1 wherein saidshroud includes means for maintaining substantially uniform air pressureat said shroud discharge outlet.

6. A rotary combustion engine comprising a hollow housing, a pair havingspaced end walls interconnected with said housing to form a cavity, arotor shaft extending in said cavity and rotatably journaled by said endwalls, intake means communicating with said cavity, exhaust dischargemeans communicating with said cavity, a combustion zone in said cavitybetween said intake means and said exhaust discharge means whereby saidhousing includes a sector which extends between said intake means andsaid exhaust discharge means and which is relatively hotter than theremaining portions of said housing, a first plurality of coolingpassages extending axially along the outer surface of said housingsector, a second plurality of cooling passages extending arcuately alongthe outer surface of one of said end walls, a centrifugal fan driven bysaid rotor shaft and hving a circumferencially extending radially openoutlet, a shroud defined by walls means enclosing said fan and extendingradially outwardly from said fan outlet, said shroud communicating withsaid radially open circumferencially extending fan outlet and includinga shroud discharge outlet, and duct means independently communicatingeach of said first and second pluralities of cooling passages with saidshroud discharge outlet.

7. A rotary combustion engine comprising a hollow housing, a pair ofspaced end walls interconnected with said housing to form a cavity, arotor shaft extending in said cavity and rotatably journaled by said endwalls, intake means communicating with said cavity, exhaust dischargemeans communicating with said cavity, a combustion zone in said cavitybetween said intake means and said exhaust discharge means whereby saidhousing includes a sector which extends between said intake means andsaid exhaust discharge means and which is relatively hotter than theremaining portions of said housing, a first plurality of coolingpassages extending axially along the outer surface of said housing, asecond plurality of cooling passages extending arcuately along the outersurface of one of said end walls, a third plurality of cooling passagesextending arcuately along the outer surface of the other of said endwalls, a fan driven by said rotor shaft, a shroud enclosing said fan andincluding an air discharge outlet, and duct means independentlycommunicating each of said first and second and third pluralities ofcooling passages with said shroud discharge outlet.

8. A rotary combustion engine in accordance with claim 6 wherein saidfan is located adjacent to the other of said end walls, and wherein saidduct means includes a duct extending in said housing adjacent to saidfirst plurality of cooling passages and communicating between saidshroud discharge outlet and said second plurality of cooling passages.

9. A rotary combustion engine in accordance with claim 6 wherein saidshroud includes an axially inner member mounted on one of said end wallsand an axially outer member mounted on said inner member and havingtherein an air inlet for said fan.

10. A rotary combustion engine in accordance with claim 9 wherein saidair inlet is concentric with said rotor shaft.

11. A rotary combustion engine in accordance with claim 6 wherein saidshroud discharge outlet has :1 limited arcuate extent and is alignedarcuately with said first plurality of cooling passages.

12. A rotary combustion engine in accordance with claim 6 wherein saidshroud includes means for maintaining substantially uniform air pressureat said shroud discharge outlet.

13. A rotary combustion engine comprising a hollow housing, a pair ofspaced end walls interconnected with said hollow housing to form acavity, a rotor shaft extending in said cavity and rotatably journaledby said end walls, fuel intake means communicating with said cavity,exhaust discharge means communicating with said cavity, a combustionzone in said cavity between said intake means and said exhaust dischargemeans, whereby said housing includes a sector which extends between saidintake means and said exhaust discharge means and which is relativelyhotter than the remaining portions of said housing, a centrifugal fandriven by said rotor shaft and having a circumferentially extendingradially open outlet, a shroud defined by first wall means enclosingsaid fan and extending radially outwardly from said fan outlet, saidshroud communicating with said radially open circumferencially extendingfan outlet and including a shroud discharge outlet, a plurality ofcooling fins extending radially outwardly from said housing sector ingenerally parallel relation to said rotor shaft, second wall meansincluding a first portion engaging the radially outer ends of saidcooling fins to provide a first plurality of cooling passages extendingaxially of said housing, and a second portion extending from said firstportion and cooperating with said shroud to define a conduit extendingfrom said shroud discharge outlet to said first plurality of coolingpassages, a second plurality of cooling passages extending arcuatelyalong the outer surface of one of said end walls, a third plurality ofcooling passages extending arcuately along the outer surface of theother of said end walls, and duct means independently communicating eachof said second and third pluralities of cooling passages with saidshroud discharge outlet independently of each other and independently ofsaid conduit.

14. A rotary combustion engine in accordance with claim 13 wherein saidfan is located adjacent to one of said end walls, and wherein said ductmeans includes a duct extending in said housing adjacent to said firstplurality of cooling passages, and communicating between said thirdplurality of cooling passages and said shroud discharge outlet.

15. A rotary combustion engine in accordance with claim 13 wherein saidshroud includes means for maintaining substantially uniform air pressureat said shroud discharge outlet.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIN Patent No 3 845 747Datgd November 5 1974 lnventofls') James A. Donohue, John H. Winston,and Harry M. Ward,III

It: is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Claim 4, line 67, "therein should be --wherein-.

---wal1 means m Claim 6, line 8, "having" should be Claim 6, line 24,"walls means should be Signed and sealed this 1st day of July 1975 SEAL)Arrest:

Ca EIARSHALL DAN-N RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks

1. A rotary combustion engine comprising a hollow housing, a pair ofspaced end walls interconnected with said hollow housing to form acavity, a rotor shaft extending in said cavity and rotatably journaledby said end walls, fuel intake means communicating with said cavity,exhaust discharge means communicating with said cavity, a combustionzone in said cavity between said intake means and said exhaust dischargemeans, whereby said housing includes a sector which extends between saidintake means and said exhaust discharge means and which is relativelyhotter than the remaining portions of said housing, a plurality ofcooling fins extending radially outwardly from said housing sector ingenerally parallel relation to said rotor shaft, a centrifugal fandriven by said rotor shaft and having a circumferentially extendingradially open outlet, a shroud defined by first wall means enclosingsaid fan and extending radially outwardly from said fan outlet, saidshroud communicating with said radially open circumferentially extendingfan outlet and including a shroud discharge outlet, and second wallmeans including a first portion engaging the radially outer ends of saidcooling fins to provide a plurality of cooling passages extendingaxially of said housing, and a second portion extending from said firstportion and cooperating with said shroud to define a duct extending fromsaid shroud discharge outlet to said plurality of cooling passages.
 2. Arotary combustion engine in accordance with claim 1 wherein said shroudfurther includes an axially inner member mounted on one of said endwalls and an axially outer member mounted on said inner member andhaving therein an air inlet for said fan.
 3. A rotary combustion enginein accordance with claim 2 wherein said air inlet is concentric withsaid rotor shaft.
 4. A rotary combustion engine in accordance with claim1 therein said shroud discharge outlet has a limited arcuate extent andis aligned arcuately with said cooling passages.
 5. A rotary combustionengine in accordance with claim 1 wherein said shroud includes means formaintaining substantially uniform air pressure at said shroud dischargeoutlet.
 6. A rotary combustion engine comprising a hollow housing, apair having spaced end walls interconnected with said housing to form acavity, a rotor shaft extending in said cavity and rotatably journaledby said end walls, intake means communicating with said cavity, exhaustdischarge means communicating with said cavity, a combustion zone insaid cavity between said intake means and said exhaust discharge meanswhereby said housing includes a sector which extends between said intakemeans and said exhaust discharge means and which is relatively hotterthan the remaining portions of said housing, a first plurality ofcooling passages extending axially along the outer surface of saidhousing sector, a second plurality of cooling passages extendingarcuately along the outer surface of one of said end walls, acentrifugal fan driven by said rotor shaft and hving a circumferenciallyextending radially open outlet, a shroud defined by walls meansenclosing said fan and extending radially outwardly from said fanoutlet, said shroud communicating with said radially opencircumferencially extending fan outlet and including a shroud dischargeoutlet, and duct means independently communicating each of said firstand second pluralities of cooling passages with said shroud dischargeoutlet.
 7. A rotary combustion engine comprising a hollow Housing, apair of spaced end walls interconnected with said housing to form acavity, a rotor shaft extending in said cavity and rotatably journaledby said end walls, intake means communicating with said cavity, exhaustdischarge means communicating with said cavity, a combustion zone insaid cavity between said intake means and said exhaust discharge meanswhereby said housing includes a sector which extends between said intakemeans and said exhaust discharge means and which is relatively hotterthan the remaining portions of said housing, a first plurality ofcooling passages extending axially along the outer surface of saidhousing, a second plurality of cooling passages extending arcuatelyalong the outer surface of one of said end walls, a third plurality ofcooling passages extending arcuately along the outer surface of theother of said end walls, a fan driven by said rotor shaft, a shroudenclosing said fan and including an air discharge outlet, and duct meansindependently communicating each of said first and second and thirdpluralities of cooling passages with said shroud discharge outlet.
 8. Arotary combustion engine in accordance with claim 6 wherein said fan islocated adjacent to the other of said end walls, and wherein said ductmeans includes a duct extending in said housing adjacent to said firstplurality of cooling passages and communicating between said shrouddischarge outlet and said second plurality of cooling passages.
 9. Arotary combustion engine in accordance with claim 6 wherein said shroudincludes an axially inner member mounted on one of said end walls and anaxially outer member mounted on said inner member and having therein anair inlet for said fan.
 10. A rotary combustion engine in accordancewith claim 9 wherein said air inlet is concentric with said rotor shaft.11. A rotary combustion engine in accordance with claim 6 wherein saidshroud discharge outlet has a limited arcuate extent and is alignedarcuately with said first plurality of cooling passages.
 12. A rotarycombustion engine in accordance with claim 6 wherein said shroudincludes means for maintaining substantially uniform air pressure atsaid shroud discharge outlet.
 13. A rotary combustion engine comprisinga hollow housing, a pair of spaced end walls interconnected with saidhollow housing to form a cavity, a rotor shaft extending in said cavityand rotatably journaled by said end walls, fuel intake meanscommunicating with said cavity, exhaust discharge means communicatingwith said cavity, a combustion zone in said cavity between said intakemeans and said exhaust discharge means, whereby said housing includes asector which extends between said intake means and said exhaustdischarge means and which is relatively hotter than the remainingportions of said housing, a centrifugal fan driven by said rotor shaftand having a circumferentially extending radially open outlet, a shrouddefined by first wall means enclosing said fan and extending radiallyoutwardly from said fan outlet, said shroud communicating with saidradially open circumferencially extending fan outlet and including ashroud discharge outlet, a plurality of cooling fins extending radiallyoutwardly from said housing sector in generally parallel relation tosaid rotor shaft, second wall means including a first portion engagingthe radially outer ends of said cooling fins to provide a firstplurality of cooling passages extending axially of said housing, and asecond portion extending from said first portion and cooperating withsaid shroud to define a conduit extending from said shroud dischargeoutlet to said first plurality of cooling passages, a second pluralityof cooling passages extending arcuately along the outer surface of oneof said end walls, a third plurality of cooling passages extendingarcuately along the outer surface of the other of said end walls, andduct means independently communicating each of said second and thirdpluralities of cooling passages with said shroud dIscharge outletindependently of each other and independently of said conduit.
 14. Arotary combustion engine in accordance with claim 13 wherein said fan islocated adjacent to one of said end walls, and wherein said duct meansincludes a duct extending in said housing adjacent to said firstplurality of cooling passages, and communicating between said thirdplurality of cooling passages and said shroud discharge outlet.
 15. Arotary combustion engine in accordance with claim 13 wherein said shroudincludes means for maintaining substantially uniform air pressure atsaid shroud discharge outlet.